The NIH-wide Genes and Environment Initiative (GEI), developed to support efforts for identification of major genetic susceptibility factors for high impact diseases and potential causative environmental exposures, recently launched the Genome-Wide Associations (GWA) component to support genome-wide association studies in both the initial discovery or replication phases. To support the complexities of such an ambitious effort, the Department of Biostatistics at the University of Washington has convened a team of experts to serve as the Coordinating Center (GWA CC) to provide the necessary organizational and statistical expertise for integration of data, development of methodologies and tools for both data harmonization and analyses, and for the administration of those tasks needed for a large multi-site scientific study of this nature. Specifically, the GWA CC will serve as a centralized resource to facilitate and support the activities of the GEI-GWA program and for GEI-supported replication and fine mapping activities, sequencing, and functional studies by (1) developing, harmonizing and providing documentation of phenotypic data from studies included in this initiative and to provide the storage and transfer of all datasets between the National Center for Biotechnology and study sites as needed;(2) contributing to the development of these strategies by providing statistical support for modeling and selecting options for replication and follow-up studies, selecting targets for sequencing and functional studies;developing statistical methodology for harmonization of data to be applied to the combined set of phenotypes, identifying samples for genotyping according to selected platforms;providing statistical support for further development of analytic methods;and supporting data analyses of the combined dataset to study investigators;(3) providing administration and coordination of all activities by facilitating study communications across all sites by developing and using tools designed to allow and encourage information exchange;coordinating all Steering Committee and working group meetings and conference calls to include distribution of pertinent materials and production of all interim and final reports for the Steering Committee, Project Office, and working groups, (4) administering all tasks necessary for development of policies, documentation of and sharing of data, and (5) supporting all other efforts requested by the Steering Committee or Project Office as needed for successful coordination of the GEI-GWA Study. Coordination of the GEI-GWA Study will be done in a spirit of collaboration using creative and flexible approaches while providing leadership in statistical methodology and approaches to project management. This proposal brings together a strong team of statistical geneticists, biostatisticians, epidemiologists, programmers, analysts and project management staff with many years of related experience to successfully accomplish the goals of the GEI-GWA.